This is a continuation application by the Ontario Familial Colorectal Cancer Registry (OFCCR), an active member of the Cooperative Family Registries for Colorectal Cancer Studies (CFR), to complete, maintain, update and expand our infrastructure of data and biospecimens, for current and future collaborative studies in the broad area of colorectal cancer research. Over the past four years, the OFCCR has collected family history data, personal risk factor and food frequency information, blood and tumor samples from over 1,300 incident colorectal cancer cases identified by the Ontario Cancer Registry, using common protocols developed by the 6 CFR centers. We are also collecting similar data from over 4,000 relatives of the aforementioned probands and about 900 age and sex-matched (to the probands) population controls. This large infrastructure will now be augmented for further collaborative genetic studies by: 1) accruing incident colorectal cancer cases less than age 50 in Ontario (and family members) from 2003 to 2007; 2) registering and expanding prevalent high risk colorectal cancer kindreds from the Familial GI Cancer Registry in Toronto, and 3) enhancing a newly formed collaboration with colleagues in Newfoundland who are developing a similar family-based colorectal cancer registry. In addition, the OFCCR, in cooperation with the CFRs, will develop and implement both active and passive follow-up protocols for existing and newly recruited subjects as well as family members. These activities will ensure the maintenance of a high quality, and up-to-date family registry which will be used both locally, and in collaboration with other scientists, in studies of gene-gene interactions, gene-environment interactions, genetic epidemiology, pharmacogenomics, gene discovery, psychosocial and behavioral research. The OFCCR will also be a rich resource of high-risk subjects for future recruitment into colorectal cancer prevention trials.